[Python-Dev] Multilib strikes back

[M.-A. Lemburg]

James Y Knight wrote:
> 
> On Nov 22, 2004, at 9:19 PM, Mihai Ibanescu wrote:
> 
>> On Mon, Nov 22, 2004 at 02:01:24PM -0600, Skip Montanaro wrote:
>>
>>>     Mihai> How about a _pyconfig_32.h and a _pyconfig_64.h and have
>>>     Mihai> pyconfig.h include one or the other, depending on the
>>>     Mihai> environment?
>>>
>>> How would that be detected?  As I understand the original bug report, 
>>> the
>>> user gave gcc a -m32 flag.  How would that be reflected in the 
>>> environment?
>>
>>
>> With the help of Jakub: pyconfig.h would have something close to:
>>
>> #include <limits.h>
>>
>> #if CHAR_BIT == 8 && LONG_MAX == 0x7fffffff
>> #include "_pyconfig_32.h"
>> #elif CHAR_BIT == 8 && LONG_MAX == 0x7fffffffffffffff
>> #include "_pyconfig_64.h"
>> #else
>> #error Unable to detect architecture word length
>> #endif
>>
>> This way, if the compiler is in 32-bit mode, the proper file is included.
> 
> 
> I think that is the wrong solution. The right solution is to put 
> pyconfig.h in an arch-specific directory.

+1

I wonder why 64-bit Unixes seem to ignore the fact that header
files may very well include platform specific settings. Currently,
only libs and binary files are separated according to platform.

However, this is a OS builder related problem and not one that
Python will need to solve.

> In current standards, that'd 
> probably have to be /usr/lib*: e.g. /usr/lib/python2.4/include/ and 
> /usr/lib64/python2.4/include/.  In the proposed multiarch standard 
> (http://www.linuxbase.org/~taggart/multiarch.html), that would be 
> /usr/include/i386-linux/ and /usr/include/x86_64-linux/.
 >
> Different, but slightly related: since .py files aren't platform 
> dependent, /usr/lib* is really the wrong place for them. They should be 
> going in /usr/share/python2.X/ not /usr/lib*/python2.X/. Obviously the 
> .so files still need to go in /usr/lib*, though, so that might be a bit 
> of a trick.

That won't work: extensions often place their .so files into their
package directories. As a result they need a platforma specific
location as well.

-- 
Marc-Andre Lemburg
eGenix.com

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